Chevron Corp. has put up for sale its minority stake in Australia's biggest and oldest LNG project, the North West Shelf (NWS), after drawing interest from potential buyers, the company said June 18.

The move marks a long-awaited shake-up of ownership in the 30-year-old project as it runs out of gas and shifts towards becoming a facility that will process gas into LNG for third parties.

"Chevron Australia has made the decision to market its nonoperated one-sixth interest in the North West Shelf project, following a number of unsolicited approaches from a range of credible buyers," the company said in an emailed statement. It gave no further details.

The project partners have invested more than A$34 billion (US$23 billion) over the life of the project, however, the gas fields that feed the NWS LNG plant are expected to start running out in the next few years.

The plant owners are looking to line up supply from new fields, and plan to charge a fee to process that gas from third parties.

Chevron's stake could fetch $3 billion to $4 billion, said one analyst, who declined to be named.

The sale is not a must, as the U.S. giant has said it is on track to meet its $5 billion to $10 billion target for asset sales between 2018 and 2020.

Chevron said it remains committed to its Gorgon and Wheatstone LNG projects, also in Western Australia.

Analysts said it made sense for Chevron to sell its NWS LNG stake now, after it failed to seal a deal to supply gas to the plant from its undeveloped Clio and Acme fields.

Likely suitors include infrastructure investors as well as NWS LNG operator and co-owner Woodside Petroleum, analysts said.

"[Woodside] is well-positioned financially and has announced it is ready and looking for M&A opportunities in Australia," said David Low, an analyst at consultants Wood Mackenzie.

Woodside declined to comment.

The other owners of the project are BHP Group, BP Plc, Royal Dutch Shell Plc and a joint venture between Japan's Mitsubishi Corp. and Mitsui & Co. (US$1 = 1.4541 Australian dollars)